In the past, the art has employed differing techniques for determining the conductivity of solid electrolyte. For example, an alternating electrical current has been introduced across two electrodes between which a film of the electrolyte is located. Such an arrangement can be sealed within a container containing an inert atmosphere so as to protect the film from moisture. Moreover, due to the temperature dependence of ionic conductivity, this container has been placed in a constant-temperature chamber. However, such arrangements have been considered bulky and cumbersome.
Recently, an improved conductivity cell has been produced. This cell, which was developed by Ib Olsen of Valence Technology, Inc., Denmark, is known as syringe-type electrolyte conductivity cell and is illustrated in FIG. 1 (as disclosed in U.S. patent application Ser. No. 08/042,315 which is filed as Attorney Docket No. 1154 and entitled "ELECTRO CHEMICAL TEST CELL FOR TRANSPORT AND CONDUCTIVITY MEASUREMENTS" which application is incorporated herein by reference in its entirety).
In FIG. 1, such a conductivity cell comprises a plastic barrel, 1, adapted from a syringe by cutting off the tip of the barrel, and pair of metal, electrode-rods 2, each having at least one O-ring, 3, located thereon.
In such a cell, a sample of unpolymerized electrolyte can be placed into the syringe barrel and sealed between the two metal rods or electrodes. This sample can then be cured "in-situ" by employing ultraviolet radiation, or heat. Alternatively, a sample of thermoplastic material can be drawn into the cell (syringe barrel) at elevated temperatures where the thermoplastic is fluid. The sample may then be allowed to cool in the cell.
While this arrangement provides an improved method of determining conductivity, it suffers from a problem associated with temperature control. As previously discussed, conventional temperature control techniques are often quite bulky and can involve a large refrigerator-like chamber.
Accordingly, the need still exists for a means to provide a constant temperature to this syringe-type test cell.
It is therefore an object of the present invention to provide a constant temperature jacket for such a conductivity test cell.
Another object of the present invention is to provide an improved apparatus for measuring the conductivity of a solid electrolyte.
These and other objects will become apparent from the specification and claims which follow.